There are a variety of conditions which result in pathologic chronic collection of bodily fluids within the body of a person. Chronic pericardial effusions, normopressure hydrocephalus, hydrocephalus, chronic pulmonary effusion, pulmonary edema, and ascites are but a few of the conditions in which chronic fluid collections persist and result in increased morbidity and mortality.
These types of conditions currently are treated typically by one of three methods: 1) external drainage with a high-risk of infection and long-term requirement for multiple punctures, 2) drainage to another body cavity, or 3) treatment with various drugs. For pericardial effusions and hydrocephalus of all types, the treatment of choice is typically drainage to another region of the body. For pericardial effusions this entails a pericardial window, a highly invasive procedure in which a large section of the external heart cavity is removed. For hydrocephalus, the treatment typically involves the use of a ventriculo-peritoneal shunt draining the cerebrospinal fluid into the peritoneal cavity. This device frequently becomes clogged due to the proteinaceous environment of the peritoneal cavity and requires removal or revision.
One problem which may arise with the chronic collection of bodily fluids is ascites, which is a highly debilitating complication associated with many medical conditions including liver failure and congestive heart failure. Untreated ascites can result in respiratory compromise, compression of the inferior vena cava (a vital blood vessel) and spontaneous bacterial peritonitis (a life-threatening condition). In order to treat chronic ascites, medicine has turned to both drugs and surgery.
The drugs required to treat ascites are typically long-term and frequently result in complications. The most common pharmaceutical treatment of ascites involves the use of diuretics to remove fluid from the patient's body through their urine. The difficulty with this treatment, though, is that fluid is removed from the entire body, including the circulating volume of blood, and can result in excessive loss of fluid required to perfuse the vital organs of the human body. Thus, even with frequent application, the medicines frequently fail. In such cases, surgical, or invasive; procedures are indicated.
Currently the most common surgical treatment is paracentesis. In paracentesis, the peritoneal fluid is drained through the abdominal wall via the insertion of a needle through the abdominal wall into the peritoneal cavity. This procedure is only a temporary solution as the ascites quickly refills the peritoneal cavity in most chronic conditions. Furthermore, repeated paracenteses places the patient at increased risk for a life-threatening infection of their peritoneal cavity. Other surgical/invasive procedures typically involve treatment of the cause of the ascites (for example, the Transjugular Intrahepatic Portosystemic Shunt) but these measures also frequently result in complications, which are often serious and are thus performed infrequently.
Many of the existing commercially available devices provide little improvement over the intermittent punctures of paracentesis and result in increased rates of infection or other complications if left in place for any length of time. Therefore, there is a need for a device which effectively reduces the need for repeated punctures or abdominal incisions and thereby reduces the risk of serious infection.